1. Field of the Invention
The invention concerns a dispenser for simultaneously delivering two compositions from separate chambers of the dispenser.
2. The Related Art
Not all chemical ingredients are mutually compatible. Separation may be required because of chemical reactivity or physical incompatibility during storage. Certain health and beauty aids, cleaning compositions and dental formulas may be benefited by packaging that separates respective components of these products. Of particular concern have been dental products which require simultaneous delivery of mutually reactive sodium bicarbonate and hydrogen peroxide.
The art has described a number of packages that separate reactive components by placing their compositions in different chambers. Only at the point of use are these compositions combined. For instance, U.S. Pat. No. 5,020,694 (Pettengill) and U.S. Pat. No. 5,038,963 (Pettengill et al) describe rigid piston-type multi-cavity dispensing containers for simultaneous co-extrusion of two or more flowable materials in a predetermined proportion. These rigid containers have the advantage of relatively good control over the co-extrusion process. On the other hand, a considerable amount of plastic is involved in their construction. For environmental reasons, packaging with less plastic is sought.
Another suggestion in the art has been to utilize side-by-side collapsible tubes for toothpaste compositions. Representative of this technology is U.S. Pat. No. 4,487,757 (Kiozpeoplou), U.S. Pat. No. 4,687,663 (Schaeffer) and U.S. Pat. No. 4,964,539 (Mueller). Each of these disclosures describes a pair of tubes that have been crimped at an end distant from the product dispensing cap end. Actual attempts to crimp the ends of similar tube designs have resulted in improper seals. Not only were the resultant crimps difficult to form, but leakage was also noted in several instances.
U.S. Pat. No. 5,318,203 (Iaia et al.) reports a dual-chamber dispenser which includes a cap having a dispensing base and a cover, and a pair of elongated hollow tubes. At an upper dispensing end of each of the tubes is an exit orifice and a coupling mechanism for attachment to an underside of the dispensing base. The upper dispensing end is D-shaped in cross-section. The lower end of the hollow tube is either round or oval in the cross-section. After being filled with respective product streams, the lower ends of the pair of hollow tubes are crimped together to form a seal. Although this package is a significant advance over the art, a problem exists in the dispensing of both streams equally and simultaneously from both tubes. The dispensing problem is especially notable as the package reaches exhaustion of product. Separation of the tubes by their outward bowing as product within nears depletion is another functional and aesthetic problem.
U.S. Pat. No. 5,702,033 (Beaver) embellishes upon the Iaia et al. disclosure by tapering the openings of each compartment towards a common nozzle. Yet the basic problems of even extrusion and avoidance of bowing still remain.
Accordingly, it is an object of the present invention to provide a dual chamber thin walled dispenser utilizing less plastic than rigid packages while still providing good control over co-extrusion of the components.
Another object of the present invention is to provide a dual chamber dispenser utilizing a pair of flexible tubes whose ends can readily be crimped and whose crimp provides an adequate seal.
Another object of the present invention is to provide a dual chamber dispenser from which respective separate streams can be extruded in an even manner.
Yet a further object of the present invention is to provide a dual chamber dispenser wherein respective streams from each chamber can be uniformly dispensed even when most of the stream has been extruded from the package.
Other objects, features and advantages of this invention will become more apparent upon the reference of the following detailed description and drawings illustrating preferred embodiments of the invention.